1. Field of the Invention
This invention relates to a structure for mounting a damper on a rotary shaft such as a drive shaft, propeller shaft and the like for a vehicle.
2. Description of the Prior Art
For the purpose of reducing vibration and noise of a drive line, there is a case where a mass damper is mounted on a rotary shaft such as a drive shaft and a propeller shaft (FORD FIESTA WORKSHOP MANUAL, '83.7, for example). This mass damper, as shown in FIG. 9 or 10, consists of two damper pieces 2. Each damper piece 2 is disposed around a rotary shaft 1, bolts 3 are inserted into the respective opposite ends and nuts 4 are screwed onto the bolts 3. Thus, the damper pieces 2 are mounted on the rotary shaft 1. Under such a mounting condition, an inner peripheral surface 5 of each damper piece 2 is brought into contact with the rotary shaft 1, so that the mass damper is held by the rotary shaft 1 with frictional force of contact portions. The inner peripheral surface 5 of each damper 2 is formed to have a V-shaped section. As shown in FIG. 10, the inner peripheral surface 5 of the damper piece 2 may be formed into a cylindrical surface to conform to a surface of the rotary shaft 1.
When the rotary shaft is twisted at the time of transmission of torque, relative displacement or relative slip occurs between the inner peripheral surface of each damper piece and the rotary shaft in the damper as noted above. Since the relative displacement or slip occurs repeatedly, fretting is generated.